Mechanisms will be identified which explain the strong inverse association between socioeconomic status (SES) over the life course and cardiovascular disease morbidity and mortality in the Atherosclerosis Risk in Communities (ARIC) , a bi-ethnic population-based sample of four U.S. communities. Health outcomes will include non-invasively measured subclinical cardiovascular disease, as well as fatal and non-fatal clinical disease manifestations ascertained over the course of 10 years of follow-up. Earlier life course socioeconomic status and measurements of current socioeconomic status and biomedical cardiovascular risk factors will be integrated with geocoded contemporary social environmental exposures to assess their impact on cardiovascular function, metabolic impairments, allostatic load, and subclinical and clinical disease. Multilevel analyses will be performed with the goal of identifying pathways by which socioeconomic status is related to cardiovascular disease, considering relevant health behavior, life styles, psychosocial stressors/support mechanisms, chronic infection/chronic inflammatory burden, autonomic nervous system dysfunction, and sustained metabolic impairments. The potential modification of the above associations by the social environment will be addressed by these analyses, as well as putative differences by gender and ethnicity.